An estimated 31 kids a day in 2010 were treated in emergency rooms for bouncer-related injuries. Total injuries sustained on bouncers that year? More than 11,000.

All told, there were probably around 64,000 injuries sustained in the bouncers between 1990 and 2010, the researchers say. Though the actual figure could have been almost 97,000 or as low as 32,000, given that these were estimates made from a sample of about 100 hospitals.

The most common injuries were broken bones and sprains or strains.

The researchers from Nationwide Children's Hospital in Columbus, Ohio, say theirs is the first study to estimate bouncer injuries using national data and to look at the types of injuries treated in emergency rooms.

"Although authors have drawn parallels between trampoline-related and inflatable bouncer-related injuries, bouncers have escaped the attention garnered by trampolines in the medical literature and public policy arena," they wrote.

So, the researchers call for guidelines for safer use of bouncers and better designs to cut down on injuries.